When Hurricane Katrina swept through New Orleans in 2005, 1,245 people died as a result and property damage was estimated at $108 billion.

A major catastrophe by any measure.

But experts say a 7.8-magnitude earthquake in Southern California would have even more devastating effects with a greater loss of life and nearly double the amount of damage to the region’s infrastructure, including critical transportation, power and water systems.

A “ShakeOut Scenario,” compiled by the U.S. Geological Survey (USGS) and multiple other agencies, estimates that a temblor of that size would kill 1,800 people, injure 50,000 and cause $200 billion in damage with long-lasting social and economic impacts.

Dr. Lucy Jones, a seismologist and chief scientist with the USGS, outlined the economic repercussions in a 2013 presentation to the American Geophysical Union in San Francisco.

“When you have a big disaster you lose a lot of money,” she said. “There are things that are broken and wealth that is lost. But also the economic activity of the region stops. All of those businesses without water, without power and without transportation are no longer producing goods and the economic wealth that had been part of that business.”

Significant building damage

The ShakeOut report estimates that all non-reinforced masonry buildings within 15 miles of the San Andreas Fault would be completely destroyed, killing many people inside. All told, the quake would result in an estimated $33 billion in building losses throughout the study’s eight-county region which includes Los Angeles, San Bernardino, Riverside, Orange, Ventura, Kern, San Diego and Imperial counties.

Federal Emergency Management Agency (FEMA) guidelines say there is a 90 percent chance that most buildings won’t collapse. In her presentation, Jones noted that a 7.8-magnitude quake would cause nearly 1,500 buildings to collapse and another 300,000 to suffer significant damage.

“In Northridge we had 230 collapses and 2,300 red tags,” she said. “So we’re accepting not only that we have a 10 percent collapse rate, but we need to think that for every one of those we have about 10 red tags — and about four yellow tags for every red tag.”

A building that has been red-tagged means it has suffered severe damage and will have to be demolished. A yellow-tagged building means it has suffered moderate damage and its habitability may be limited.

“For the ShakeOut earthquake they estimate that 1 percent of the buildings will collapse,” Jones said. “That’s a 99 percent chance that your building’s going to stay up. That sounds awfully good. It still, though, implies that 1 percent of the buildings actually collapsed And if we have 10 red tags per collapse and four yellow tags per red tag, we end saying that about half of our buildings will not be able to be occupied.”

Water system ruptured

Jones said a major quake would cripple Southern California’s water system.

“You absolutely have to have water to be able to keep on functioning, and the water supply system is one of the most vulnerable parts of our society,” she said. “You can’t really stay in your home very well if you don’t have water. Most small businesses have to have water to operate. You can’t have a beauty salon … you can’t have a restaurant without water.”

Seventy percent of the water system throughout Southern California is made with AC piping, which is extremely brittle and easily subject to breakage in the event of a quake, Jones said.

“A small business that has been out of business for six months the economists tell us won’t return,” she said. “We face the loss of a large number of small businesses in the region.”

“We see in Flint, Mich., what can happen when critical infrastructure such as fresh water is compromised,” he said.

No power for weeks

Damage to the region’s electric grid is another big concern, according to Don Daigler, director of SCE Business Resiliency for Southern California Edison.

“We anticipate that we would see widespread outages across most of our service territory,” he said. “They could range all the way up to two weeks in duration. The bulk of the power would start coming back on within 24 to 72 hours, but we could see some outages lasting up to two or three weeks.”

Daigler, a former planning director with FEMA, said SCE is prepared for the worst.

“In 2014 we started developing an all-hazards plan,” he said. “It’s a plan that would prepare you for the worst set of planning factors you’d have to worry about. We used the earthquake scenario that was built out for the ShakeOut to drive that plan.”

Daigler said Edison has performed several drills and exercises to determine what kinds of improvements would best help the utility in the event of a big quake. The company ultimately developed an incident command system that standardizes how response actions would be handled.

“It’s the same standard that all state and emergency management uses to gain access to federal grants,” he said. “We’ve also done seismic upgrades to our infrastructure. We continue to look at the survivability of the infrastructure.”

Roads, freeways closed

Jones said there are lots of inter-dependencies within the region’s infrastructure.

“When a building collapses it creates debris that sits on the road,” she said. “And when water pipes break they undermine the road bed and can wash things out. That disruption to the transportation system leads to a lot of consequences. It is very difficult to get to work and it’s difficult for emergency responders to get to the people who need help.”

Kleinhenz said there’s a lot at stake in Los Angeles, Orange, San Bernardino, Riverside and Ventura counties — a region with a thriving $1 trillion economy.

“There’s no question that having $200 billion in damage to your infrastructure would have an adverse impact on economic activity for some time,” he said. “But that $200 billion in losses would also be offset by whatever is covered by insurance.”

More than a third of Southland residents had earthquake insurance when the 1994 Northridge earthquake hit, Jones said, and FEMA was cutting checks to some homeowners in the Los Angeles area the day of the quake.

“Money was being thrown at the problem,” she said. “People were going out hiring contractors to remove the debris, to repair the buildings. Those contractors were hiring subcontractors and we very quickly got the economic engine back up and going. However, it doesn’t have to happen that way. You can end up where there’s just not enough going on and everything goes down to a lower level.”

Kevin Smith handles business news and editing for the Southern California News Group, which includes 11 newspapers, websites and social media channels. He covers everything from employment, technology and housing to retail, corporate mergers and business-based apps. Kevin often writes stories that highlight the local impact of trends occurring nationwide. And the focus is always to shed light on why those issues matter to readers in Southern California.

Join the Conversation

We invite you to use our commenting platform to engage in insightful conversations about issues in our community. Although we do not pre-screen comments, we reserve the right at all times to remove any information or materials that are unlawful, threatening, abusive, libelous, defamatory, obscene, vulgar, pornographic, profane, indecent or otherwise objectionable to us, and to disclose any information necessary to satisfy the law, regulation, or government request. We might permanently block any user who abuses these conditions.

If you see comments that you find offensive, please use the “Flag as Inappropriate” feature by hovering over the right side of the post, and pulling down on the arrow that appears. Or, contact our editors by emailing moderator@scng.com.